Plastic bags such as infusion solution bags have advantages of easy handling and simple disposal after use. Currently, polyethylene as a safe material is generally used for plastic bags prevailing in the field of medical containers.
However, since polyethylene is a plastic having high gas permeability, when easily oxidized medicine such as amino acid is contained in a medical bag, the medical bag is generally held in a plastic outer bag having gas barrier property together with an oxygen absorber.
On the other hand, to reduce costs of the outer bag, there has been a demand to impart gas barrier property to the medical bag itself and various plastic materials having gas barrier property as well as properties including flexibility, transparency and impact resistance have been considered.
A plastic material described in Patent document 1 is characterized in that it is a multilayer film having a heat sealing resin layer, a biaxial oriented polyester resin film with an inorganic oxide deposited layer, a biaxial oriented polyamide resin film and a surface protective film, wherein the deposited layer of the biaxial oriented polyester resin film is adhered to the heat sealing resin layer, the surface on the opposite side to the deposited surface of the biaxial oriented polyester resin film is adhered to one surface of the biaxial oriented polyamide resin film, and the surface protective film is disposed on the other surface of the biaxial oriented polyamide resin film.
A plastic material described in Patent document 2 is characterized in that it is a multilayer film having a polyethylene layer forming a heat sealing part, a cyclic olefin polymer layer and a polyethylene terephthalate layer with an inorganic oxide deposited layer, wherein the polyethylene layer is adhered to one surface of the cyclic olefin polymer layer and the deposited layer of the polyethylene terephthalate layer is adhered to the other surface of the cyclic olefin polymer layer.
A plastic material described in Patent document 3 is characterized in that it is a multilayer film having a heat sealing layer (ethylene polymer), a biaxial oriented film (biaxial oriented polyethylene) substrate with an inorganic oxide deposited layer and a protective film (biaxial oriented polyamide film), wherein the heat sealing layer is adhered to the surface on the opposite side to the inorganic oxide deposited layer of the biaxial oriented film substrate, and the protective film is adhered to the surface of the inorganic oxide deposited layer of the biaxial oriented film substrate.
[Patent document 1] Japanese Unexamined Patent Publication No. 2004-58336
[Patent document 2] Japanese Unexamined Patent Publication No. 2001-157705
[Patent document 3] Japanese Unexamined Patent Publication No. 2004-148681